1. Field of the Invention
The present invention relates to a magnetic recording medium on which burst patterns are formed by patterns that include recording regions and non-recording regions, a recording/reproducing apparatus equipped with the magnetic recording medium, and a stamper for manufacturing the magnetic recording medium.
2. Description of the Related Art
As examples of this type of magnetic recording medium and recording/reproducing apparatus, Japanese Laid-Open Patent Publication No. H06-111502 discloses a magnetic disk apparatus equipped with a magnetic disk on which recording track patterns and servo patterns are formed by concave/convex patterns. On the magnetic disk provided in the magnetic disk apparatus, the recording track patterns and the servo patterns are formed by concave/convex patterns formed in a magnetic layer on a disk substrate. More specifically, as shown in FIG. 22, on a conventional magnetic disk (hereinafter referred to as a “magnetic disk 10x1”), a plurality of track patterns Pw formed in belt-like shapes along the direction of rotation of the magnetic disk 10x1 (the direction of the arrow R shown in FIG. 22) and servo patterns Ps1, Ps2 formed in servo pattern regions are formed by the concave/convex patterns described above. Note that on the magnetic disk 10x1 shown in FIG. 22 and a magnetic disk 10x2 shown in FIG. 23 described later, formation regions of convex parts (recording regions) in the concave/convex patterns are shown by obliquely shaded areas and formation regions of concave parts (non-recording regions) in the concave/convex patterns are shown by the non-shaded (i.e., white) regions.
The servo patterns Ps1, Ps2, . . . are servo patterns used to detect the position of a magnetic head and thereby make the magnetic head on-track to a desired track pattern Pw. The servo patterns Ps1, Ps2 are formed as a pair to function as a burst pattern. Also, on the magnetic disk 10x1, the widths Ts of the servo patterns Ps1, Ps2 are equal to the formation pitch of the track patterns Pw (referred to as the “track pitch Tp”) and both ends in the radial direction of the servo patterns Ps1, Ps2 are positioned so as to match the centers of the track patterns Pw (the positions shown by broken lines in FIG. 22: centers of the tracks). The formation positions of the servo patterns Ps1, Ps2 differ by the track pitch Tp in the radial direction of the magnetic disk 10x1 and are separated from one another in the direction of rotation.
On the other hand, another magnetic disk (hereinafter referred to as “magnetic disk 10x2”) on which four types of pattern, servo patterns Ps1 to Ps4, are formed as shown in FIG. 23 is disclosed in the same publication. On the magnetic disk 10x2, the servo patterns Ps1, Ps2 form a pair and function as a set of burst patterns and the servo patterns Ps3, Ps4 form a pair and function as another set of burst patterns. Also, on the magnetic disk 10x2, the widths Ts of the servo patterns Ps1 to Ps4 are formed so as to be double the track pitch Tp. In addition, on the magnetic disk 10x2, both ends in the radial direction of the servo patterns Ps1, Ps2 are formed so as to match the centers (the positions shown by broken lines in FIG. 23: centers of the tracks) of track patterns Pw and both ends in the radial direction of the servo patterns Ps3, Ps4 are formed so as to match the centers of other track patterns Pw. The formation positions of the servo patterns Ps1, Ps2 differ by double the track pitch Tp in the radial direction of the magnetic disk 10x2 and are separated from one another in the direction of rotation. The formation positions of the servo patterns Ps3, Ps4 also differ by double the track pitch Tp in the radial direction and are separated from one another in the direction of rotation. In addition, the servo patterns Ps1 to Ps4 are formed so that the center in the radial direction of a burst pattern composed of the servo patterns Ps1, Ps2 and the center in the radial direction of a burst pattern composed of the servo patterns Ps3, Ps4 differ by the track pitch Tp in the radial direction.